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Subject: Re: [RFC net-next 0/8] Introducing subdev bus and devlink extension
To:     Jakub Kicinski <kuba@kernel.org>, moyufeng <moyufeng@huawei.com>
CC:     Jakub Kicinski <jakub.kicinski@netronome.com>,
        Jiri Pirko <jiri@resnulli.us>,
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        <shenjian15@huawei.com>, "chenhao (DY)" <chenhao288@hisilicon.com>,
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From:   Yunsheng Lin <linyunsheng@huawei.com>
Message-ID: <7c591bad-75ed-75bc-5dac-e26bdde6e615@huawei.com>
Date:   Tue, 1 Jun 2021 15:33:09 +0800
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On 2021/6/1 13:37, Jakub Kicinski wrote:
> On Mon, 31 May 2021 18:36:12 +0800 moyufeng wrote:
>> Hi, Jiri & Jakub
>>
>>     Generally, a devlink instance is created for each PF/VF. This
>> facilitates the query and configuration of the settings of each
>> function. But if some common objects, like the health status of
>> the entire ASIC, the data read by those instances will be duplicate.
>>
>>     So I wonder do I just need to apply a public devlink instance for the
>> entire ASIC to avoid reading the same data? If so, then I can't set
>> parameters for each function individually. Or is there a better suggestion
>> to implement it?
> 
> I don't think there is a great way to solve this today. In my mind
> devlink instances should be per ASIC, but I never had to solve this
> problem for a multi-function ASIC. 

Is there a reason why it didn't have to be solved yet?
Is it because the devices currently supporting devlink do not have
this kind of problem, like single-function ASIC or multi-function
ASIC without sharing common resource?

Was there a discussion how to solved it in the past?

> 
> Can you assume all functions are in the same control domain? Can they
> trust each other?

"same control domain" means if it is controlled by a single host, not
by multi hosts, right?

If the PF is not passed through to a vm using VFIO and other PF is still
in the host, then I think we can say it is controlled by a single host.

And each PF is trusted with each other right now, at least at the driver
level, but not between VF.

> 
> .
>